I\'m very stuck on these last questions Data Analysis: Calculate the following q

ID: 991691 • Letter: I

Question

I'm very stuck on these last questions

Data Analysis:

Calculate the following quantities and record the data in the table below.

Conclusions

Phenolphthalein is pink over the range of pH 8 – 12. Why was it a useful indicator of when the equivalence point was reached?

Suppose a student titrated a sample of monoprotic acid of unknown concentration using a previously standardized solution of NaOH.

Given the data in the figure above, what is the concentration of the unknown acid?

average volume of NaOH solution dispensed (mL) average number of moles of NaOH dispensed average concentration of the acid (mol/L)

1 mole of acid reacts with 1 mole of base

moles of NaOH added = 0.125 M x 24.68 ml = 3.085 mmol

moles of acid present = 3.085 mmol

Concentration of unknown acid = 3.085 mmol/50 ml = 0.0617 M

Phenolphthalein changes its color in the range of end point of the titration of acid with base and hence it is a useful indicator for the titration